Physics
A mass m1 = 4.1 kg rests on a frictionless table and connected by a massless string to another mass m2 = 5.9 kg. A force of magnitude F = 32.0 N pulls m1 to the left a distance d = 0.83 m. 1) How much work is done by the force F on the two block system? 2) How much work is ...January 2, 2013

Math
37% of college students say they use credit cards because of the rewards program. You randomly select 10 college kids and ask each to name the reason he or she uses credit cards. Find the probability that the number of college students who say they use credit cards because of ...November 25, 2012

chemistry
one isotope of chromium (atomic number 24) has an atomic mass of 53 amu. how many neutrons are in this particular isotope of chromium? A. 24 B. 29 C. 53 D. 77 I say ANovember 24, 2012

chemistry
amphetamine (c9h13n) is a powerful stimulant. what is the percent composition of all of the elements in this compound? A. 9%C;13%H;1%N B. 30%C;10%H;60%N C. 60%C;35$H;5%N D. 80%C;9.6%H;10.4%N I think bNovember 23, 2012

chemistry
a compound is found to be 94.1% o and 5.90% h. its molecular mass is 34.0. what is its molecular formula A. H3O2 B. OH C. H2O D. H2O2 I think DNovember 23, 2012

Physics
A roller coaster is initially at a height of 40 m above the ground and has an initial velocity of 15 m/s. Using conservation of energy, find the velocity of the roller coaster at a height of 5 m above the ground.November 21, 2012

chemistry
in the formula for calcium bromide (CaBr2), what does the subscripted two indicate? A. the bromide atom has a charge of 2- B. the bromide atom has a charge of 2+ C. there are two bromide atoms for every calcium atom. D. there are two calcium atoms for every bromide atom I say C.November 20, 2012

Science
The "resistant" threshold for gemifloxacin is >1 mg/L while the "resistant" threshold for sulfamethoxazole is >512 mg/L. Explain why there might be this great disparity of values in resistance thresholds (512-fold) for each antibiotic ...November 6, 2012

physics
Just an explanation without numbers would be awesome, i just want to understand the correct steps to take. Thanks!October 3, 2012

physics
Ice fishing equipment weighing 3,000 N is pulled at a constant speed V = 0.5 m/s across a frozen lake by means of a horizontal rope. If the coefficient of kinetic friction is 0.05, what is the work done (in J) by the fisherman in pulling the equipment a distance of 500 m?October 3, 2012

Chemistry
A mixture of ethane and ethene occupied 35.5 L at 1.000 bar and 405 K. This mixture reacted completely with 110.3 g of O2 to produce CO2 and H2O. What was the composition of the original mixture? Assume ideal gas behavior Im pretty sure i use dalton's law of partial ...September 19, 2012

Physics
A tennis ball is thrown horizontally from an elevation of 20.60 m above the ground with a speed of 19.0 m/s. (a) Where is the ball after 2.00 s for the horizontal and vertical position? (b) If the ball is still in the air, how long before it hits the ground? If the ball is ...September 13, 2012

Math
Fiind the area bounded by the parabola y^2 = 8x, the x axis and the line x=2August 21, 2012

Physics
a quarter sits at the bottom of a wishing well where the gauge pressure reads 294 kPa. If the quarter has a diameter of 24mm, what is the total force acting on the top surface of the quarter? Note: Atmospheric pressure = 101.3August 20, 2012

calculus
Can someone please show steps as I am having a hard time understanding. The position (in meters) of a particle is modeled by y=x^3-12.5x^2+51x-67.5, where xis in seconds. Find the max, min and point(s) of inflection.April 23, 2012

calculus
This is just for study for exam coming up and says it could be worth up to 12 marks. Not understanding vry well the twoApril 23, 2012

calculus
The position (in meters) of a particle is modeled by y=x^3-12.5x^2+51x-67.5, where xis in seconds. Find the max, min and point(s) of inflection.April 23, 2012

calculus
A balloon is being filled at a rate of 4000 cm^3/min. How fast is the surface area of the ballon increasing when the radius is 125 cm? V=4/3pir^3, SA=4pir^2April 23, 2012

physics
A certain dog whistle operates at 23.5 kHz, while another (brand X) operates at an unknown frequency. If neither whistle can be heard by humans when played separately, but a shrill whine of frequency 9200 Hz occurs when they are played simultaneously, estimate the operating ...April 23, 2012

managerial economics
Qd=15.0-0.2P where Qd is annual quantity demanded in millions of units and P is the wholesale price. Incurred cost of $60 million. Production cost is $5/unit. (1) what is wholesale price, (2) production annually, (3) annual profit? Given this is a monopoly with an expiring ...February 29, 2012

chemistry
A solution was made by dissolving 10.0g of a nonvolatile nonelectrolyte compound in 100.0g of water froze at -0.93C. What is the approximate molecular weight of the substance. (for water..kf=1.86C/m) (m is molality)December 12, 2011

Physics
A frog in a hemispherical bowl, as shown below, just floats in a fluid with a density of 1.26*10e3 kg/m3. If the bowl has a radius of 6.16 cm and negligible mass, what is the mass of the frog?June 28, 2011

math
Jeff is thinking of a function machine.He says that the output is 5 when the input is 4.What are two different rules that he could be thinking of.March 10, 2011

physics
train is approaching the station at a speed of 20m.s sounds a 220 hz horn. What frequency does an observer on the station platform hearFebruary 28, 2011

physics
What do we know? r=6.38x10^6m T=1 day=86,400s Part A: T=2(pi)r/V ==> V=2(pi)r/T a=V^2/r (Plug & chug) Part B: Now, what do we know? Only T=1 day=86,400s. We no longer know r. Latitude we'll say is represented by "l". So r(l) = r cos l Once you find that radius...February 23, 2011

Physics
A car is approach a corner too fast and locks up the brakes at point A and holds them on for 12.5 M to point B. The car then moves from point B at a constant speed and does into the corner. At Point C because the car is still going to fast it goes out of control and leave the ...January 20, 2011

chemistry
What products are formed when sucrose is heated in an aqueous sulfuric acid solution? What role does the acid play?January 16, 2011